GPS for Dummies.pdf - Engineering Surveyor

Chapter 18: Navigating Web Road Maps291On Christmas Day, 1998, a German driver out fora spin in a GPS-equipped BMW drove his carinto a river as he dutifully followed the directionsof his in-car navigation system. Despitethe stop signs, he continued down a ferry rampand drove into the Havel River, slowly sinking inabout 12 feet of water. Fortunately, the driverand his passenger were not injured. The digitalmap displayed in his dashboard showed abridge when it actually should have beenmarked as a ferry crossing — and the drivertrusted his BMW more than his common sense.This is a rather extreme case, but it does illustratean important point: Street maps willMap accuracyalways have some errors in them, and you can’texpect 100 percent accuracy. Software companies,Web sites, and map data vendors do trytheir best to keep maps current and up-to-date.(Most map Web sites even have ways to reporterrors in maps and driving directions.) However,when you consider the 3.95+ million miles ofpublic roads in the United States — with constant,ongoing construction — keeping mapsaccurate can be a daunting challenge. So trynot to get too frustrated if a map Web site occasionallymakes a boo-boo. And watch out forferry crossings.Street map Web site advantagesSome of the advantages that street map Web sites offer are that they’re Free: Street map Web sites are one of those valuable resources that youcan still get for free on the Internet. The companies that host these mapsites stay in business by selling advertising, offering other mappingproducts and services to corporate customers, or charging for premiumservices. Easy to use: Street map Web sites are very simple to use. They offerbasic mapping features and easy-to-understand user interfaces. Available almost anywhere: If you have an Internet connection and aWeb browser, you can find street addresses and create maps from justabout anywhere you can access the ’Net. More frequently updated: One of the big selling points to maps on Websites is they can be updated more frequently than maps that come withPC software; which tend to be updated annually. (However, I’ve yet tosee a map site provide details on how often and which maps have beenupdated.)Street map Web site disadvantagesSome of the drawbacks to using street map Web sites include Limited POIs: PC street map software packages have a large number ofPoints of Interests (POIs) on maps such as gas stations, restaurants, andother businesses and services. Most street map Web sites don’t show